AI Glossary · Last reviewed August 2026

LLM

· Large Language Model

Hand-written by a real person. Reviewed against current practice in August 2026.

Definition

A neural network trained on huge amounts of text, capable of generating, summarising, and reasoning about language.

Why it matters

Large Language Models are the foundation of the current AI revolution. GPT-4, Claude, Gemini, Llama - these are all LLMs. Every AI writing tool, coding assistant, and chatbot you use is built on one.

Understanding LLMs helps you cut through marketing hype. When a tool claims to be "AI-powered," knowing which LLM it uses and how it is configured tells you what it can actually do.

How it works

4 steps

STEP 01

Pre-training on text

The model reads billions of documents from the internet, learning grammar, facts, reasoning patterns, and world knowledge.

STEP 02

Alignment training

Human reviewers rate model outputs, and the model is fine-tuned using RLHF to be helpful, harmless, and honest.

STEP 03

Prompt processing

When you send a message, the model processes your input through its transformer layers to understand context and intent.

STEP 04

Token-by-token generation

The model predicts the most likely next token repeatedly, building up a coherent response word by word.

Related terms

From the glossary

Frequently asked questions

Is every AI an LLM?+

No. LLMs are one type of AI model focused on text. Other AI models handle images, audio, video, or structured data prediction without being language models.

How big is a large language model?+

Size is measured in parameters, the numeric weights learned during training. Models range from a few million parameters for small local models to hundreds of billions for frontier models like GPT-4.

Can LLMs reason?+

They can simulate multi-step reasoning through chain-of-thought prompting, but current research debates whether this constitutes true reasoning or very sophisticated pattern matching.

New to LLM?

See the tools that use it.

The fastest way to understand LLM is to see it inside real products. Browse hand-reviewed tools that put it to work, each one checked by a person before it was listed.

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